A pilot plant aimed at demonstrating the feasibility of the artificial photosynthesis photosynthesis technology developed within the scope of Germany’s Rheticus I and II research projects was officially opened earlier today at Evonik’s site in Marl. The plant uses carbon dioxide and water to produce chemicals, with the necessary energy being supplied by electricity from renewable sources.
The Rheticus projects are joint research projects that were first launched in 2018 by Evonik and Siemens. In the Rheticus I project, the two companies worked for two years to develop the technically feasible basis for artificial photosynthesis using a bioreactor and electrolyzers. The second project, Rheticus II, involved designing, building and now running the present pilot plant. Rheticus II will run until 2021, by which time Evonik and Siemens Energy will have a platform technology available that can produce valuable products such as specialty chemicals or artificial fuels from CO2 - in a modular and flexible manner.
The Federal Ministry of Education and Research is funding the various project stages with more than €6 million.
The researchers were inspired by nature in the development of the technology. Just as plants use solar energy to produce sugar, for example, from CO2 and water in several steps, artificial photosynthesis uses renewable energies to produce valuable chemicals from CO2 and water through electrolysis with the help of bacteria. This type of artificial photosynthesis can serve as an energy store, to help close the carbon cycle and to reduce carbon dioxide pollution in the atmosphere.
Basically, the design of the plant features a CO electrolyzer, a water electrolyzer and a bioreactor. In the electrolyzers, carbon dioxide and water are converted into carbon monoxide (CO) and hydrogen (H2) with electricity. This synthesis gas is used by special microorganisms to produce specialty chemicals, initially for research purposes. These are starting materials for special plastics or food supplements, for example.
Over the next few weeks, the composition of the synthesis gas and the interaction between electrolysis and fermentation will be optimised. In addition, a unit for processing the liquid from the bioreactor will be set up to obtain the pure chemicals.
After successful completion of the current Rheticus project phase (Rheticus II), Evonik and Siemens Energy will have a platform technology at their disposal that can produce energy-rich and valuable substances such as specialty chemicals or artificial fuels from CO2 - in a modular and flexible manner.
The Rheticus research project is a spin-off of the Copernicus projects, one of the largest research initiatives of the German Federal Government on energy system transformation.